Facsimile recorder



p 19425 W. G H. FINCH 2,296,274

FACSIMILE RECORDER Filed May 10, 1940 13 Sheets-Sheet l I INVENTOR. 7 William lf auch ATTORNEY.

v Sept. 22, 1942; w. G. H. FINCH 5,

FAGSIMILE RECORDER Filed May 10, 1940 13 Sheets-Sheet 2 T m QM INVENFOR.

BY 5 m 4 ATTORNEY.

Sept. 22, 1942- w. G. H. FINCH mcsmm nscommn Filed May 10, 1940 13 Sheets-Sheet 3 FIG-f5.

F I 4 INVENTOR.

uhlliam gJiL-S'Tncll BY Z 2 ATTORNEY.

FACSIMILE RECORDER Filed May 10, 1940 13 Sheets-Sheet 4 ii 50 712 F'|G.7 463 ATTORNEY.

Sept. 22, 1942. w. G H. FINCH FACSIMILE RECORDER 1s sheets-sheet 5 Filed May 10, 1940 F'IGJ I.

INVENTOR. 'llkuaam g-fliflncb BY w ATTORNEY.

Sept. 22, 1942.. w. G. H. FINCH mcsmm: RECORDER Filed May 10, 1940 Q .13 Sheets-Sheet 6 INVENTOR. llhlham Jag- BY i ATTORNEY.

FIGJY FIGJS.

Sept. 22, 1942. 2

W. G. H. FlNCH FACSIMILE RECORDER 13 Sheets-S File d May 10. 1940 heat 7 ATTORNEY.

BY 5 a p 22, 1942- w. G. H. FINCH 2,296,274

Filed May 10, 1940 FIG.'22.

Sept. 22, 1942.

FACSIMILE RECORDER Filed ma 10, 1940 I :5 Sheets-She et 9 1-" P U '28:, l i

FIG.23-

INVENTOR.

a ATTORNEY.

Sept. 22, 1942. w. a. H. FINCH FACSIMILE RECORDER Filed May 10, 1940 13 Sheets-Sheet l0 INVENTOR. g. ATTORNEY.

I William BY Z p i942- -w. G. H. FINCYZH 2,296,274

FACS IMILE RECORDER Filed May 10, 1940 13 Sheets-Sheet ll INVENTOR. williamgjflfinch BY Z a z ATTORNEY.

w. G. H. FINCH FAC'SIMILE RECORDER Sept. 22, 1942.

Filed May 10, 1940 15 Sheets-Sheet 12 1N VENTOR. William 9f. at 71 W ATTORNEY.

Sept. 22, 1942.

w. s. FINCH FACS IMILE RECORDER Filed May 10, 1940 13 Sheets-Sheet l5 INVENTOR. William gffifl'nch ATTORNEY.

Patented Sept. 22, 1942 UNITED STATES PATENT OFFICE racslmmnncoannn William G. n. Finch, Newtown, Conn. Application May 10, 1940, Serial No; 334,404

14 Claims. (01. lie-6.6)

This invention relates to the transmission and reception offacsimile signals and more particularly to synchronizing apparatus for use in connection therewith, said synchronizing apparatus particularly at the receiving end being so arranged that a minimum number of parts are brought to a stop in order to await any particular synchronizing signal.

Heretofore in the operation of facsimile appa ratus and particularly of facsimile receivers, it

has been necessary in order to obtain line by line synchronism in line by line scanning to halt some portion of the reception apparatus sometime after the end of a scanning cycle and just before the commencement of the next one.

The apparatus then was started by the reception of the synchronizing impulse which permitted the scanning member of the receiving apparatus to commence a new scanning excursion simultaneously with the commencement of the scanning excursion at the transmitting end.

Accordingly it was necessary to design the apparatus so that the scanning means itself was brought to a stop at the end of a scanning cycle and before the beginning of the next scanning cycle and it was necessary to design meansfor holding the. entire scanning apparatus in a stationary position pending the receipt of the synchronizing impulse.

power, it was necessary to bring the drive shaft of the sprockets, the sprockets themselves, and the chain to a stop at the end of each scanning excursion in order to bring the stylus to a stop and then to bring all of these elements into movement once more immediately upon the receipt of the synchronizing impulse.

Likewise in the case of the stylus mounted upon an oscillating arm wherein the oscillating arm was continuously reciprocated back and forth, scanning on its excursion in one direction and returning in the opposite direction while the paper advanced; and wherein the oscillating arm was driven in any suitable manner by, for instance, a cam connection to a shaft, it was necessary to bring the shaft, cam and oscillating arm to a stop immediately before the commencement of the scanning excursion in order to await the synchronizing impulse and then to bring all of these elements into motiononce-more immediately upon receipt of the synchronizing impulse.

The dimculty arising from the necessity of bringing all of these elements to a stop was not merely academic. In many cases of facsimile reception there are a hundred or more scanning Accordingly any even slight vibration inherent in the operation of the reception apparatus chronizing impulse were present in each of the general types of receiving apparatus; Thus,

whether the receiving apparatus comprised a multistylus chain drive or'an oscillating stylus mounted on a scanning arm or alight beam scanning device moving longitudinally along a revolving drum, it became necessary to stop a relatively great mass at the end of a particular scanning cycle and to bring this relatively great mass into motion once more immediately upon receipt of the synchronizing impulse.

might tend seriously to mar the picture. Accord. ingly in prior facsimile apparatus it was essential that the apparatus be mounted on a heavy cast iron base and it was further useful to incorporate therein various complicated shock absorbing devices which would tend to inhibit whatever vibration necessarily resulted from the continuously recurring starting and'stopping of masses which, with respect to the size of the actual scanning stylus or beam were relatively great.

Thlssame not greater force in the light beam scanning re-' ception apparatus wherein the light beam traversed a reception drum longitudinally-while the drum revolved. In this case it was necessary not ,merely to bring the light beam scanning appawere driven from the 'motor or other source of ratus itself to a stop but also to bring the receiving drum to a stop upon the completion of a difllculty was present with equal if impulse to initiate the actual scanning operation.

Another object of the present invention is to so mount and relate the actual scanning member itself to the various other moving parts that it is.

only the relatively small mass of the actual stylus or other scanning element which must be stopped or the motion of which must be changed in order to obtain proper synchronization.

Still another object of the invention is to obtain proper synchronization while the moving parts of the receiving scanner may maintain constant uninterrupted. unchanged movement.

Still a further object of the present invention is to provide a synchronizing apparatus wherein the speed of the receiving apparatus may be cut down to almost that of the transmitting apparatus.

Still another object of the present invention is to provide a means for obtaining automatic phasing at the start of the picture transmission and for automatically phasing the receiving apparatus at various selected intervals controllable from the transmitting station.

Since in many cases, facsimile receiving apparatus is to be used in the home by unskilled operators, it is essential that virtually all of the operations thereof be either greatly simplified or if possible, controlled from the transmitting station.

Accordingly, the automatic phasing means herein provided will increase the utility of this apparatus in the home. Furthermore, the automatic phasing means herein provided may be arranged to coact with the scanning element in order toreposition the scanning element with respect to its drive apparatus at selected intervals in order to ensure that the scanning element will remain aligned with its driving elements.

There are many other objects and uses of the present invention part of which will be apparent and part pointed out in the following description and drawings, in which:

Figure l is a top plan view of a multi-stylus facsimile recorder utilizing the principle of my invention.

Figure 2 is a side view of the apparatus of Fig ure 1.

Figure 3 is an end view of the apparatus of Figure 1.

Figure 4 is a cross-sectional view taken on line 4-4 of Figure 3.

Figure 5 is an end view taken along the line 5-5 of Figure 1.

Figure 6 is a view partly in cross-section showing the front of the scanner and is taken from line 6-6 of Figure 1.

Figure 7 is a view partly in cross section taken along line 'I-l of Figure 1 showing the resetting means for the stylus.

Figure 8 is a cross-sectional view taken along line 8-8 of Figure 6. I

Figure 9 is a top view partly broken away taken along line 9-9 of Figure 1.

Figure 10 is a cross-sectional view taken along line III-l0 of Figure 1.

Figure 11 is a cross-sectional view taken along line H-i i of Figure 1 showing the paper feed.

Figure 12'is a cross-sectional view taken along line l2-l2 of Figure 10.

Figure 13 is a cross-sectional view taken along line 13-13 of Figure 2 showing the chain and sprocket drive.

Figure 14 is a cross-sectional view taken along line M-M of Figure 13.

Figure 15 is a cross-sectional view taken along line l5-l5 of Figure 2.

Figure 16 is a cross-sectional view taken along line lS-IB of Figure 1.

Figure 17 is a cross-sectional view taken along line 'lI-ll of Figure 1.

Figure 18 is a cross-sectional view taken along line l8-l8 of Figure 1'7.

Figure 19 is a view of the portion of the paper surface contacted by the stylus and showing guides for the scanning stylus of Figure 1.

Figure 20 is a. cross-sectional view taken along line 20-20 of Figure 19.

Figure 21 is a cross-sectional view taken along line 2I-2l of Figure 19.

Figure 21a is a view corresponding to a portion of Figure 6 showing a' modified form of relay construction.

Figure 21b is a cross-sectional view on line 2llr-2Ib if Figure 21a.

Figure 22 is a top plan view of light beam scanner recorder utilizing the principles of the present invention.

Figure 23 is an end view partly in cross-section taken along line 23-2: of Figure 22.

Figure 24 is a cross-sectional view partly in elevational taken along line 26-24 of Figure 22.

Figure 25 is a cross-sectional view partly in elevation taken along line 25-25 of Figure 22.

Figure 26 is a cross-sectional view taken on line 26-26 of Figure 22.

Figure 2'7 is a view corresponding to a portion of Figure 23 showing another position of the parts thereof.

Figure 28 is a view corresponding to a portion of Figure 26 showing another position of the parts thereof.

Figure 29 is a top plan view taken along line 29-29 of Figure 23 showing one position of the synchronizing elements.

Figures 30, 31, 32 and 33 correspond to Figure 29 showing the different positions of the parts thereof.

Figure 34 is a top plan view of an apparatus illustrating a modified application of my invention to an oscillating arm scanner.

Figure 35 is an elevation partly in cross-section taken along line 35-35 01' Fig. 34.

Figure 36 is a cross-sectional view taken along line 36-36 of Figure 34.

Figure 37 is an enlarged view of a portion of Figure 35.

Figure 38 is a top plan view illustrating a slight modification of the construction 01 Figure 34 as likewise applied to an oscillating scanning arm.

Figure 39 is a cross-sectional view partly in elevation taken online 38-39 of Figure 38.

Figure 40 is a cross-sectional view partly in elevation taken on line "-46 of Figure 38.

Figure 41 is an enlarged view of a portion of Figure 40.

Figure 42 is a view taken along line 42-42 of Figure 38.

Referring now to Figures 1, 2 and 3, the recorder of this embodiment is arranged for compactness and simplicity of construction and operation consistent with quality high speed recording. The recorder may be designed for mounting in a portable cabinet of a type and size similar, for instance, to a radio console cabinet, a suitcase or other similar stationary or portable article. The recorder arrangement may also be correspondingly spaced for this purpose. The

styli assemblies 02 are mounted at equidistant points on the chain II at intervals substantially equal to the width of the recording sheet 00.

Stylus assemblies 02 are movable in a plane parallel to the base and individually and successively cooperate with the recording sheet once for each revolution of the chain 0 I v .An electric motor." is supported beneath the recorder base 50 by bracket 01 which in turn is secured to the under side of the recorder base by the bolt 08. Motor 56 is preferably of the nonsynchronous type operable from an alternating or direct current power supply.

' Motor 00 is coupled to a drive shaft 03 through worm gear arrangement enclosed in housing 00 shown in section in Figure 13. Any suitable coni. nection may be made between the motor 08 and the arrangement enclosed in housing 00. A preferred form shown particularly in Figure 2 is the flexible cable BI which is used to connect the motor shaft with the gearing arrangement.

The synchronizing magnet 1| supported beneath the base 50 as seen in Figures 2 and 13 is Figure 4 and will be hereinafter described in connection with .the further description of the procthat the movement of the paper will be exactly responsive to receive cyclic impulses and coopcrates with the driven mechanism to establish a proper phase position for each stylus of each of the stylus assemblies 52 at the beginning of each recording excursion of each of the stylus assemblies. This cyclic synchronizing action which con stitutes the major portion of this invention will be hereinafter described in greater detail 'and will be more fully understood when the action of the various parts of the recordingunit is firstexplained. a

The motor 58 through the iiexible cable I drives the worm 80 within the housing 00. This worm 00 meshes with the'worm gear 0| which by means of the 'key 02' is mounted upon the drive gear 8i results in rotation of the shaft 03. The shaft 03 is positioned by and rotates in the journals 04 and 05. the end 00 of the shaft 03 being captured in the collar 01, which is connected thereto by the pin 03.

Compression spring 09 is located on the shaft 03 between the collar 01 and the thrust bearing 00 and thus serves accurately to position the shaft 03, while it rotates and thus serves further to reduce any possible frictional loss at the base of the housing.

The opposite end 9| of the shaft 83 is likewise captured in a collar 32 by means of the screw 03. This collar bears against the thrust bearing 94 shaft 03 in such manner that rotation of the worm .which in turn carries the thrust of the end of the shaft 0i. Compression spring 00 thus accurately positions the shaft 03 against the two thrust bearlugs and the thrust bearings 30 and 94 serve to isolate the shaft 03 from the remainder of the mechanism and make it possible to provide areleasable drive or clutch 00 for the sprocket 53.

While this releasable drive or clutch 95 appears. in Figures 3 and 13, it is shown most clearly in the opposite end thereof, I25.

with a cooperating gear IIiI.

es of obtaining and maintaining synchronism.

The sprocket I3 is not driven directly by the shaft 03 but instead is driven by the hollow shaft or sleeve I00 (Figure 13) which rotates about the shaft 03 and which is independent of shaft 83. Shaft I00 carries at the upper end thereof, as

seen in Figure 13, an insul-atingsleeve II" which is secured thereto in any suitable manner as,- for instance, by the screw I02. The insulating sleeve IOI has a. peripheral extension I 03 thereon which, by means of the screws I04 carries the sprocket 53. The sprocket 53 is thus insulatedly supported upon the shaft I00 and when the shaft I00 is driven, the sprocket 03 is caused thereby to rotate and hence to move the chain II in the appropriate direction as is hereinafter described.

Appropriate bearings Iii may be provided for the sleeve I00 in suitable extensions or mountings II of the base 50. The track member II1,

mounted on the insulating support II8, serves as a guide for the stylus assemblies in the manner hereinafter described; these members. for this purpose, extend longitudinally along the path of the stylus assemblies and guide the assemblies around the sprockets.

The driven synchronized shaft carries a spiral gear I20 (Figures 13 and 3), which drives the gear I2I. The gears I20 and I2I are the source of power for the .paper drive and hence ensure synchronous with the operation of the scanning device.

The gear I2I is keyed to the rod I22 which is mounted in suitable bearings I23 and I24 'on the underside of the base 50. The rotation of the rod I22 results in rotation of the worm at This worm meshes with the gear I36 which in turn is keyed to. rod I01 and hence rotates the same. 10 as well as Figure 3.)

Rotatable rod I31 is mounted in appropriate Jbearings I40 and HI, the'bearing I40 being se-- cured by screws I42 to a bracket I43 which in turn is. supported on the base 50 and'the bearing I4I being provided by a suitable bore in the base 50.

The rod t31 carries at the opposite end thereof from the gear I36 a worm I60 which meshes (SeeFigure 3 and especially Figure 10.) Worm gear IGI rotates the paper feed roll I62 in a manner hereinafter to be described.

In a suitable embodiment of this form of the invention, as shown in Figure 3, a supporting cabinet indicated by the dotted lines of said figure may be used. The recorder base 50 sets into recesses at the top corners I10 of the bottom section "I.

A removable cover I12 '15 fitted onto the bottom section of the cabinet IN. A transparent window I13 may be set above the recording area in order to permit direct viewing of the recording as it is performed; the transparent window may simply be an opening or may have a glass or any other transparent. protective surface. A roll of sensitized paper 200 is mounted beneath the recorder base 50 between the brackets 20I20I (see Figures 2 and 3), The rear side 203 of the cabinet may be hinged at 204 to permit the insertion of the roll of recording paper withbut otherwise making it necessary to disassemble the recorder.

The recording sheet 55 passes from the roll 200 Q (See Figure through an opening 205 in the recorder base 58 whence it is then threaded over the guide roll 286 around the platen 281 over the drive roll I62 and onto the take up ml] 238 (see also Figure 11).

A plurality of spaced rollers 288, Figures 1, 2, l0, and 11, preferably of rubber are arranged on a rod 289 in such a manner as to press the record sheet 55 against the feed roller I62 during the recording operation. The pressing rod 289 is mounted at either end in sockets 2I8 of the brackets 2i i. The brackets 2 are mounted on the ends of the rod 2I2 (see dotted lines of Figure 1).

Spiral spring 2|3 is at one end secured at 2I4 to the rod 2I2 at the other end at 2I5 biases the brackets 2| i in such direction as to press the presser rod 283 upon the feed roll I62 and hence to force the rubber rollers 288 upon the feed roll.

A crank arm 228 is provided for separating the rubber rollers-288 from the feeding roll I62 when it is desired to thread the sheet 55 between the spring biased pressure rolls 288 and the feed roller H2. As seen in Figure 3, a cam or eccentrically positioned disk 22I is arranged on the axis of support of the lever or crank arm 228 and coacts with the finger 222 secured to the rod 2I2.

Rotation of the handle 228 results in corresponding rotation of the cam 22I thus raising the finger 22 and thereby rotating the rod 2l2 against the mechanical bias of the springs 2I3 and thereby rotating the brackets 2H and moving the pressure roller 288 away from the feed roller I62.

In order further to assist in the threading operation, a knurled hard rubber knob 238 (Figure 2) may be secured to the left end of the shaft supporting the feed roller I62. knob 238 feed rollers I62 may be independently driven and record sheet 55 may be advanced until all the recorded matter projects beyond the pressure rollers 208.

The recording sheet may then be torn at the region beyond the pressure rollers and the rel,

corded matter may then be withdrawn from the facsimile unit by removal of the take up r011 238.

As is seen in Figures 16 and 17, the take up roll 238 is removably supported by the drive shaft 248 and the tail stock 24! as will be hereinafter more specifically pointed out.

The recording paper in the present invention is positively fed in the appropriate direction for successive line by line scanning and the tension is uniformly maintained across the recording region of the recording sheet 55 no matter how wide the particular sheet may be.

As shown in Figure 18, the free end 258 of the recording sheet 55 is inserted in the slot 25I in the spool 252 of the take up roll 238. The take up roll 238 is mounted for rotation between the frame up-rights I43-I43 by means of the driving shaft or plate 248 and the tail stock arrangement 24L Drive shaft or plate 248 is connected with the gear 268 through the friction clutch 26l 262 as seen in Figures 1 and 16.

Gear 268 is driven through the idler gear 218 by the gear 2H which in turn is mounted upon and rotates with the shaft of the feed roller I62. The gearing ratio between the gear 2'" and the gear 268 is designed to overdrive take up roll 238 to maintain a constant tension in the record sheet 55 during the normal feeding operation of recording.

A frictional slip occurs at the over driven feed By turning the I roll 238 to keep sheet 55 taut as will be further described in detail in connection with Figures 18 and 17. The feed or drive roll I82 is operated through the gear I8I as heretofore described particularly in connection with Figure 10. Figure 10 shows in section the connection between the gear I GI and the shaft 288 of the feed roll The roller I62 is secured by pins 28I or any other suitable means to the shaft 288, the said shaft 280 being mounted in suitable bushings 282 in the uprights I43. The gear IBI is mounted on the extension 288 of the shaft 288 and is rotatable with respect to said extension.

A washer 283 is pinned at the end of the extension 290 of the shaft 288 and abuts the outer end of the hub 284 of the gear I6l in order to retain the gear I6l in fixed axial position. A pawl 285 is mounted near the periphery of the gear Ill and an associated ratchet 288 is pinned to the extension 298 of the shaft 288 in order to effect a positive drive connection between the gear HI and the roller shaft 288.

The surface of the feed roll I82 is metallic in order to afford a continuous electrical contact to the recording sheet for electrochemical recording action. The metallic portion of feed roll I62 is connected to ground or frame potential forming the opposite potential to that of the stylusassembly, As seen in Figure 12, engagement of pawl and ratchet 285286 occurs when the gear I6I rotates in a counterclockwise direction. A positive drive is thus effected between the gear I6I and the drive roller I62. In the proper counterclockwise direction during the continuous feeding of the record sheet 55 while a recording is being made thereon.

When the knob 238 as seen in Figures 1 and 2 is manipulatedto turn the shaft 288 counterclockwise, that is in the sheet feeding direction ratchet 285 slips with respect to pawl 285 permitting the feed roll I62 to be advanced independently of the continuous drive thereof through gear I6I.

Manual rotation of shaft 288, and roller I62 causes a corresponding rotation of take up roll 238 through the gearing arrangements 283, 218, and 2' in the manner hereindescribed in connection with Figure 1. Any recorded matter on sheet 55 may thus be manually advanced onto the take up roll 238 for removal'from the facsimile unit.

Each stylus of the present invention is rigidly guided when it is in recording position. In the present embodiment three individual stylus assembles 52 are shown mounted on the link belt or chain 5| at equidistant spacings substantially corresponding to the width of the recording to be made upon the sheet 55.- After one stylus has passed through the recording excursion, the next successive stylus is thus in position for starting its recording excursion. The link belt 5| affords a rigid positive driving means for the styli.

The whole mobile stylus assembly including the chain drive 5| and sprockets 53 and 64 and the guide roll 388 are insulatingly mounted with respect to the remainder of the facsimile unit. The record sheet 55 is at the potential of the frame or base of the unit which is at ground potential.

The stylus assembly is insulated from the frame and is at the opposite potential.

In order to ensure a rigid linear path for each stylus during the recording excursion, means are provided for maintaining thechain M at a predetermined tension or tautness. This means, is

provided at the left end 6: Figure 2 where means for maintaining the predetermined tension in thelinkbelt orchain "are shown.

A compression spring H is arranged to me chanically bias a rod :04 and hence also the member 302 towards the left of Figure 2. Spring "5 is so designed that its force will be sufllcient to keep the belt or chain properly taut ior carry ing the stylus assemblies 52 successively in their recording path by tending to drive the sprocket 54 on its slidable mounting away from the sprocket 53.

Any temperature variation or any other variation which would tend to expand or contract the belt 5| or any wear which may occur in the chain orbelt 5| may automatically be compensated for by the continuous automatic action of the spring 3". A predetermined constantly maintained adjustment of the tension oi the chain or belt 5| is thus effected.

A set screw 230 is arranged on the side of member 302 opposite that of the spring M5 and is used to hold member 302 further against spring 315 when it is desired to remove the chain 5| from the associated sprocket wheel.

After the chain 5| is mounted upon the sprockets 53 and54 set screw 320 should be clear oi the member 302 after proper adjustment has been eifected in order that biasing action oi the spring 315 may be effective to maintain proper continuous adjustment of the chain 5|.

Figure is a cross sectional view along line l5l5 through the compensating mounting ior,

the sprocket 54. Sprocket 54 is secured to the insulating post or-hub 301 having a concentric bushing 325 rotatably mounted on the rod 323.

slidable member 302 with respect to the rod 303.

The slot 33] in the base permits the member 302 to slide back and forth in response to the various tensionlng eil'ects exerted between chain 5| and the spring 3l5.

As seen in Figures 9 and 11, the stylus assembly 52 is mounted on the chain 5| in any suitable manner as, for instance, by a pair of pins' 400-. 400 which pass. through the openings in the chain originally designed for the link pins thereof and which are engaged in the brackets 40l and 402 of the main stylus assembly support 403. i he main stylus assembly support 403 has an additional front bracket 404 forming a U-shaped channel 405 between the bracket 404 and the main support 403.

A similar complementary U-shaped channel 406 is formed at the top of the main stylus support 403 by the plate 401 having the angular dependent flange 403 at one side thereof and the additional flange 403 at the opposite side which registers with the chamfered side 0 of the bracket 40l. Screws 4 pass through openings in the plate 401 into the main support 403. Compression springs 442 are captured between the heads of each of the screws 4 and the upthe plate downwardly and serving to tend to narrow the distance between the base of the U-s'haped' channel 400 and the base of the U-shaped channel 435.

- A slidable stylus support 420 having projecting rails 42l and 422 is mounted on the main stylus assembly support member 403, the rails 42! and 422 being engaged in .the U-shaped channels 405 and 403. The slidable stylus support carries a rotatable stylus 425 which is I mounted on the shaft 425 which in turn is rotatably carried in the brackets 421. The brackets 421 are as is seen particularly in Figure 7 extensions oi the pivotally mounted member 423 which, as seen in Figures 9 and 11, is spring biased by means of the spring 423 towards such position that the stylus 425 is forced outwardly from the stylus supporting member 403.

The slide 420 which supports the stylus is slidable in the channels 405 and 403 and is frictionally retained in such channels by means of the spring pressure of spring 2 upon the plate 401 which tends to'narrow the distance between the bases of the said channels.

That is, although the slide which supports the stylus may move longitudinally with respect to the channels nevertheless the frictional engagement is such that the slide 420 tends to remain a: saiig'position with respect to its support mem- The support member 403 carries on the under I side thereof the slotted pulleys 430 which engage the rail H1 mounted upon the insulating support 3. These slotted pulleys 430 serve to position the front of the stylus assembly with respect to the rail. The rail of the stylus assembly carries the conical pulleys 43l mounted on the post 432 extending downwardly from the bracket 402.

A compression spring 433, is placed between the under side oi the conical roller 43i and the head 434, of the .post 432 and serves to bias the conical roller 43l so that its apex tends to ride close to the under side of the bracket 402.

' and the rail 1. The brackets 401 and 402 are so arranged that a channel 440 is formed therebetween, the said channel registering with the periphery of the sprockets 54 and 53 when the stylus assembly and the portion of the chain upon which it is mounted passes over the said sprockets, the said channel 440 receiving the said sprockets and the stylus assembly being thereby so arranged that it will not in any way interfere with the operation of the chain In suitable cases where that may be desirable, the lower rail 422 of the stylus carriage 420 may, as is seen in Figures 5 and 7, have a series of teeth 450 therein forming a rack. A gear segment or wheel 45l is pivotally mounted at 452 upon a dependent bracket 453 supported by the main support 403 of the stylus assembly, the said gear segment 45l meshing with the rack 450 and being so arranged that rotation of said gear segment will result in corresponding movement of per side oi the flange plates 401 thus pressing 7 the rack 450 and a corresponding sliding motion of the stylus carrier 426 within the channels 465 and 466 of the stylus assembly 52.

The chain is so arranged that when the picture is being received, the said chain is always in continuous motion without any necessity for the chain or any portion of the driving mechanism thereof to come to a stop at that time.

Nevertheless in spite of this fact the arrangement of the present stylus and the cooperating synchronizing elements hereinafter described is such that synchronization may be had for each scanning excursion of each stylus and the actual rolling stylus 425 may be brought to a stop for the purpose of obtaining such synchronization without the necessity for stopping even the stylus assembly itself or anything connected therewith.

In other words, the synchronizing apparatus of the present invention does not coact with any of the driving elements whatever of the sprockets and the chain itself and even the movement of the stylus assembly and the supports thereof is constant and continuous during the recording.

The slidability of the subsidiary stylus carriage 426 within the U-shaped channels 465 and 466 is the sole means of the permitting synchronization. The relative mass of the stylus upon the picture or upon the recording operation.

In other words, instead of having the synchronizing operation take place in such manner that the moving mass of the chain and all of the stylus supports and sprockets which drive the chain as well as the shafts which drive the sprockets are brought to a stop, it is necessary only to interfere with the forward movement of the stylus carriage 426 momentarily until the receipt of the synchronizing impulse in order to obtain the necessary synchronization.

Accordingly, as is seen in Figures 6 and 8, the synchronizing apparatus operates only upon the subsidiary stylus carriage 426 and does not interfere with the operation of any other portion of the mechanism and in fact is so arranged that should there be any tendency for it to interfere in any other portion of the mechanism or should the stylus carriage 420 be moved to such position that it may tend to be removed from the main support 463 of the stylus assembly 52, then the hold upon the stylus carriage will be released so that the stylus carriage might proceed with the remainder of the mechanism.

As is seen in Figures 6 and 8 the synchronizing mechanism comprises the synchronizing magnet H which is mounted in any suitable man- .coact with and when energized to attract the armature 462 the said armature 462 being pivoted at 463 and being biased by the tension spring 464 away from the magnet II. The tension spring 464 is connected at one end to the pin 465 of the armature 462 and atthe other end is connected to the pin 466 which is mounted upon the bracket 46! which in turn is also supported from the base 56.

The synchronizing lever 468 is pivotally mounted on the pin 469 which is also supported on the bracket 461. The synchronizing lever 466 is so arranged that the portion 468 thereof is of greater mass and weight than the portion 466a thereof so that the natural tendency of the lever 466 is to rotate in a clockwise direction with respect to Figure 6, its mounting upon the pin 46! being sumciently frictionless in character to permit of such rotation.

As is seen in Figure 8, the lever 466 is so positioned with respect to the stylus assembly 62 that it will abut against only the leading edge of the subsidiary stylus carriagev 426 and will not in any way engage any other portion of the main stylus assembly.

The lever 466 is restricted against the counterclockwise movement which the balancing of its weight would otherwise create by the pin 416 of the protective lever 4' which is also pivoted on the pin 469. prises two arms, one arm 41! having increased mass or weight and the other or tripping am "In being of lesser mass or weight, the arms of the lever 4' being so arranged that the two are normally biased to rotate in clockwise direction with respect to Figure 6.

The possible clockwise rotation of the protective lever 4' is inhibited by the stationary pin 412 which is mounted upon the bracket. Thus immediately before the synchronizing impulse is received, the synchronizing lever 466 is arranged in the position shown in Figure 6 where its arm 466a is disclosed in the path of the subsidiary stylus carriage 426 while its arm 466' is supported on the pin 416 of the protective lever "I. The protective lever 41! is so arranged that its arm "la is in the path of the main portion of the stylus assembly 52 and its other arm 4" is supported on the stationary pin- 412.

The arm 466a of the synchronizing lever 466 as well as the arm 4l|a of lever portion II project through the opening 466 in the base 56, the

said opening being sufficiently large to permit of the operation hereinafter described.

The arm 4660. is arranged atthe beginning of the scanning excursion, that is it is, with respect to Figure 1, set at the left hand side of the sheet 55. Thus it is arranged so that it will interrupt the movement of the stylus carriage 426 at the beginning of each scanning excursion. When the chain 5i is moved so that stylus assembly 52 arrives at the beginning of a scanning excursion, the chain 5| and the entire stylus assembly 52 continue their movement without interruption. (This, it should be noted, is directly opposite to anything previously performed in the facsimile.

art.)

The arm 468a however is so arranged that it will abut against the leading edge of the subsidiary stylus carriage 426 and hold the said subsidiary stylus carriage 426 stationary with respect to the left hand side of the sheet and hence stationary with respect to the beginning of the scanning line.

Accordingly, owing to the continued movement of the chain 5i and of the remainder of the stylus assembly 52, the subsidiary stylus carriage 426 will slide in the U-shaped channels 465 and 466 of the main stylus assembly and will continue assembly 52 have reached the synchronizing arm 468 so that the leading edge of the subsidiary stylus carriage 426 contacted the said arm at the The protective lever 4'" also comsembly 52 was in the positionshown by the dotted lines, then although the stylus assembly their movement to the position shown by the solid lines, the subsidiary stylus carriage by reason of r 2,290,274 time when the right hand end of the stylus as- 1 Accordingly, in ordinary operation unless substantial accidental mlsphasing of a serious and V unusual type should occur the arm 4'Ila should 7 52 and the chain will have nevertheless continued the fact that itwas thus held stationary will have with respect to the stylus assembly 52, been apparently moved backwards to await the synchronizing impulse which would permit it to commence its scanning excursion.

In order to'ei'fect this operation the am 408 of the lever 460 is held against counterclockwise motion under the influence of the force supplied by the stylus assembly 52 to the subsidiary stylus assembly 420 by the detent 4'0l in the armature 462 which engages the pawl-402 at the end of the arm 400'.

On receipt of a synchronizing impulse, the magnet H is energized and attracts the armature 452. When the armature 402 is attracted, the detent 48l is pulled away from the pawl 402 and nothing now prevents counterclockwise rotation of the lever 450.

The frictional engagement of the plate 401 against the subsidiary stylus carriage 420 is such that while it will yield and permit the stylus carriage to move backward with respect to the stylus rarely comeinto operation for the purpose herein'described but it is present as a safety factor in order to prevent the subsidiary stylus carriage 420 which is very light in weight and very small in size from being accidentally removed from the stylus assembly 52 and'thus becoming lost.

, The synchronizing magnet II is energized upon the receipt of synchronizing impulses in order to operate the synchronizing levers and in order to release the synchronizing lever 468 to permit the subsidiary stylus carriage '420 to begin the scanning excursion. For this purpose, the current must be made to flow through the magnet Ii in time to receive the synchronizing impulse.

Accordingly, the driven shaft I00 (Figure 13) of the sprocket 53 which drives the chain carries a earn 500 -(Figures 13 and 14) which is arranged, to disconnect the current from the stylus assembly and to make the circuit to the synchronizing magnet whenever a scanning excursion is com-'- assembly when the lever arm 460 is held in fixed position, it will nevertheless permit the stylus carriage to move forward with the stylus assembly and to movethe lever arm 4600 out of the way when the opposite end 48I of the lever 460 isnot engaged by the detent 48l.

Accordingly-upon receipt of the synchronizing impulse the ability of the lever arm 450 to impede the movement of the subsidiary stylus carriage fore immediately upon the receipt of the syn-- chronizing impulse the subsidiary stylus carriage 420 starts to move with its stylus assembly and commence the scanning excursion at the beginning of the scanning line. I

The one danger that may arise where a nontechnical or home user is operating the recording unit is that improper or unpracticed operation thereof may possibly result in the withdrawing 0f the subsidiary stylus carriage 420 from the stylus assembly 52; but the lever arm "I is provided to obviate this possibility.

The arm 41Ia of the lever 4' is so arranged that it will contact the mainor unslidable portion of the stylus assembly. When the main portion of the stylus assembly strikes the arm 41in, it willcause the said arm to rotate in a counterclockwise direction. The chamfered portion 405 of the arm 4ll' of the lever 4' will then strike the pin 486 of the armature 462 and owing to the counterclockwise rotation of the lever 4" move the pin towards the synchronizing magnet II and accordingly therefore likewise move the armature 462 in that direction in order to disengage the pawl 482 of the arm 460' of the lever 460, thus releasing the subsidiary stylus carriage 420 from the stopping action of the arm- 458a, and hence permitting the stylus carriage to continue its movement with thestylus assembly 52.

The arm 411a of the lever 4' is so spaced and arranged that it will not merely engage the main pleted and whenever a synchronizing impulse is thus to be received. 1

The cam 500 has a lug 50! extending therefrom for this purpose. A rod 502 is carried in an opening 503 of the base 50 and is so arranged that one end thereof bears against the cam 500 and the other end thereof bears against the central contact 504 of a cam switch 505.

- The central contact 504 of the cam switch 505 is spring biased in such manner that it tends always to drive the rod 502 against the side of the I cam 500. Normally the current flows from con% tact 504 into contact 500 of the cam switch 505 in order to energize the tyli and to record the pulse to be received and to be impressed upon the synchronizing magnet and hence to permit the starting of the scanning excursion at the proper moment.

In order for the lug50l to be in position at the termination of each scanning excursion, a single revolution of the sprocket wheel 53 must represent the length of a scanning line. Thus, the circumference of the wheel must equal the linear scanning distance.

By means of this arrangement only the stylus itselfrnay be moved and only the small carriage associated with it in order to obtain proper synchronism. In actual practice, the subsidiary stylus carriage 420 need not be more than a gram or two in weight and is of the relatively small size and mass shown in Figures 1, 6 and 8.

The construction of the cam switch of Figure 14 and the manner of actuation thereof is such that for most practical purposes and ordinary utilization of my invention the circuit will be changed so that the synchronizing means will be energized by the synchronizing impulse and so that the current will not flow through the styll when the synchronizing impulse is received. 

